Green hydrogen production by PEM water electrolysis up to the year 2050: Prospective life cycle assessment using learning curves

Abstract Water electrolysis technologies for producing green hydrogen are promising options for avoiding the use of fossil fuels and thus limiting climate change. Hydrogen can be used in a variety of sectors, enabling sector coupling, and strengthening the security of the energy supply through its storability. Environmental impacts provoked by green hydrogen production are comparatively low and improving manufacturing processes and technological advances will enable to further reduce the demand for raw materials and electricity and thus the environmental impacts. The objective of this study is to compare the status quo with prospective trends and target values. Learning curves of expected specific electricity demand and critical raw material (CRM) intensity are applied, and environmental impacts are subsequently analyzed via life cycle assessment. This study focuses on the polymer electrolyte membrane water electrolysis technology. As a result of the calculated learning curves, the CRM intensity could be reduced by more than 96% between 2022 and 2050. The specific electricity demand is projected to be reduced by 11.2%–22.5%. Combining the extrapolated reductions of electricity and CRM demand, a climate change impact decrease of 16.5%–28.5% is possible for green hydrogen production until the year 2050.